*Note:
Matt 12:47 is not in the two earliest codices
(before 400 CE): Sinaiticus
& Vaticanus.
But it is found in most mss.
after 400 CE.
Which explanation of these facts is more plausible?

It was omitted by accident. Scribes copying a ms. in which the same words occurred a line or so
apart sometimes omitted the words between them. Note that the ending of Matt 12:47 echoes the
narrative in Matt 12:46. Or...

It was added by later scribes to bring Matthew in line with the other synoptic versions of this
anecdote. Note parallels to Luke 8:20.

If Matt 12:47 was missing from
later mss., a scribal lapse would be clear. But since it is lacking in both of
the oldest mss., accidental omission is less likely. This verse was in the
Diatesseron,
a 2nd c. harmony of the four gospels.
But there is no evidence for it in Greek mss. of Matthew before the 5th c.
CE.

**Editorial Note: The RSV tried to salvage the awkward grammar of Mark 3:31 by translating Mark's
second participle as a main verb: "and called him." For the sake of analysis, I have restored Mark's bad
grammar.